A video-song accompaniment apparatus is a device which displays lyrics and background images as a musical program is being reproduced. As a result, a user can enjoy singing along with the musical program while viewing the displayed lyrics. Recently, the inventor of the present invention has developed a compact disk which is used in a video-song accompaniment apparatus and which can store about 2,000 musical programs and 4,000 still images. (Such a compact is typically referred to as a CD-karaoke disk or CDK disk). Furthermore, the inventor has developed a video-song accompaniment apparatus for reproducing CDK disks.
An ordinary compact disk generally comprises a lead-in area and program area. The lead in area typically contains a table of contents (i.e. an index) of all of the programs recorded on the disk, and the program area is the portion of the disk on which the programs are stored. However, in a CDK disk, the table of contents in the lead in area is not large enough to store indexing information relating to the thousands of musical programs and still images. Therefore, an index table is recorded in the program area of the CDK disk so that the many musical programs and still images can be indexed and addressed. If the CDK disk has 2,000 musical programs, each listing of an index of all of the musical programs requires at least four decimal digits.
In order to reproduce a particular musical program, a user must sequentially enter digits relating to the index number of the program via an input device. Accordingly, the time necessary to reproduce a selected program from a CDK disk depends upon the length of time between each digit input by the user. Assuming that an interval between each digit input by a typical user is about 0.3 seconds, the time required to reproduce a musical program can be estimated as follows.
The amount of musical data for each program recorded in the CDK disk is about 50 Kb, and one sector of the CDK disk can store about 2.3 Kb. Since a CD player can read about 75 sectors per second, the time for transferring the musical data from a disk to a CDK decoder is about 0.29 seconds. Thus, after the index number of a musical program is input, the user generally waits about 0.59 seconds for the CD player to begin reproducing the selected musical program (i.e. 0.3 seconds for inputting a reproduction key and 0.29 seconds for transferring the musical data to the CDK decoder).